This proposal is for the support of an interdisciplinary research proposal involving members of the Hematology Section, Department of Medicine, Baylor College of Medicine, the Surgery Department and members of the Chemical Engineering Department, Rice University. The objective of the proposal is to determine the effect of physical stresses on the blood. The specific elements of the blood to be studied include erythrocytes, platelets and soluble coagulation factors. The specific projects are designed to determine: the influence of shearing stress on red blood cells, platelets and clotting factors; the magnitude of destruction to cellular elements resultant from flow through conduits of specific design; the degree of destruction of elements of the blood related to specific cardiovascular prostheses; the influence of rheological phenomena on thrombus deposition and organization.